Question

Find the unknowns (variables)

Answer 1

Answer:

angle ecd+angle acd=180°

69°+angle acd=180°

angle acd=180°-69°=111°

now

sum of all angles of a triangle=180°

angle eaf+angle acd+angle adc=180°

30°+111°+angle adc=180°

angle adc=180°-141°

=39°

so f°=39° (by vertical opposite angle)